“This is a victory for public health and the environment,” AG Coakley said. “The Cross State Air Pollution Rule limits the hazardous pollution that some states contribute to their downwind neighbors at unreasonable levels. We applaud the Supreme Court’s decision to uphold this rule to regulate cross-state emissions and protect the public today and in the future.”

BACKGROUND:

In 2011, the Environmental Protection Agency’s (EPA) passed the Cross State Air Pollution Rule (CSAPR), which required upwind states to eliminate emissions that “contribute significantly” or interfere with National Ambient Air Quality Standards (NAAQS) in other states. Such emissions include sulfur dioxide (SO2) and nitrogen oxides (NOx), a precursor to ground level ozone and respiratory irritant.

In August 2012, the DC Circuit Court of Appeals decision in EME Homer City Generation, L.P. v. EPA vacated CSAPR, which was put in place to prevent upwind states from sending harmful air pollution, mainly from coal-fired power plants, to downwind Eastern states.

In October 2012, Massachusetts and several other states and a number of cities, filed a petition asking the Court of Appeals reverse the case, arguing that the decision against CSAPR is fundamentally inconsistent with aspects of the Clean Air Act and other air pollution decisions made by the Court.

Urging the Supreme Court to reconsider the Court of Appeals ruling, Massachusetts and other intervening states filed briefs in support of CSAPR, arguing that once EPA has set a national ambient air quality standard for certain pollutants, each affected state must propose a state plan to implement the new standard within three years, or EPA may issue a federal plan instead for states who had not adequately addressed the pollution. States also stated that under the Clean Air Act, EPA does not need to quantify how much pollution an upwind state must reduce before the state has to issue its own implementation plan.

The Supreme Court also ruled that the Clean Air Act leaves to EPA the discretion and authority to set requirements for how much pollution upwind states must reduce, so long as EPA does not exceed what is necessary to bring downwind states’ into attainment with the NAAQs.

Assistant Attorney General Fred Augenstern handled this case for Attorney General Coakley’s Environmental Protection Division with assistance from Attorney Douglas Shallcross of the Massachusetts Department of Environmental Protection’s Office of General Counsel.